Concrete dome roof form support



Aug. 15, 1961 w. o. HOFFMAN CONCRETE DOME ROOF FORM SUPPORT Filed April 7, 1958 INVENTOR [Mu/AM 0. HOFFMAN flail- AORE United States Patent Filed Apr. 7, 1958, Ser. No. 727,000 1 Claim. (Cl. 25-131) My invention relates to a means for making a dome roof of reinforced concrete.

Heretofore dome roofs of limited size have been made but the cost of making a dome roof of relatively large size is, in most cases, prohibitive because of the very expensive and extensive superstructure which must be constructed to support the forms for the concrete.

My invention relates more specifically to an improved cantilever type of device for supporting forms from and by the last previously poured slab or ring of reinforced concrete forming part of the dome.

It is the principal object of the invention to provide an improved form of frame Work for supporting a concrete form, whereby a domeshaped roof of large size may be formed at reasonable cost.

It is a more specific object to provide an improved form of frame work carrying a concrete form all supported from and by the last laid slab or ring of concrete forming part of the dome-shaped roof.

In general, the object is to provide a relatively inexpensive means for making a large dome-shaped roof without the necessity of a complete superstructure for supporting the forms for the concrete.

Other objects and various features will be hereinafter pointed out or will become apparent from a reading of the specification. In the drawings, showing a preferred form of the invention;

FIG. 1 is a fragmentary, diagrammatic top plan view of my improved device in the early stages in the production of a dome-shaped roof;

FIG. 2 is an enlarged view in side elevation of a cantilever frame carrying a form for concrete, all supported by and from a previously laid slab or ring of reinforced concrete forming part of the dome-shaped roof;

FIG. 3 is a fragmentary enlarged view in elevation of an adjustable foot for supporting the cantilever frame from the previously poured slab of concrete.

In building a dome-shaped roof, it will be desirable usually to form the circular supporting wall 5 preferably of concrete reinforced by vertical columns 6 and preferably by a generally circular reinforcing band 7 extending around the circular supporting wall for the roof. The next step would be to support a concrete form from the wall 5 or otherwise so as to permit pouring of the first circular slab or ring 8 of reinforced concrete supported from and by the circular wall 5 and preferably running around the wall and forming the first circular ring or slab of concrete of the dome-shaped roof. The subsequent slabs or rings forming the domeshaped roof would be laid on forms cantilevered from the previously formed slabs by means to be described.

My improved form supporting frame may consist of a pair of substantial beams 9-10 spaced apart from each other and rigidly secured to each other by cross beam structure 11 as will be clear. This beam structure or beam means may also include further structural or truss means such as the beam 12 carried by truss work 13 secured to the beam means heretofore described. The

Patented Aug; 15, 1961 upper beam 9 carries an adjustable support or foot member 14 which may rest on top of the previously poured slab 8 so as to adjustably support the beam structure from the top of the slab. There is a similar adjustable foot member 15 carried by the lower beam structure which may be a part of the truss work 13. The foot member 14 is carried forwardly of the frame and the foot member 15 is carried rearwardly of the structure, as shown. Thus, by adjustment of the two foot members 14-15, the cantilever structure may be moved up or dlovgn and adjusted at an angle to the previously formed s a In building a dome-shaped roof, two or more cantilever frame structures are supported from the previously poured slab such as 8 and a concrete form 16 is supported by two or more of the cantilever frames, as shown in the drawings. The cantilever frames, as heretofore indicated, may be adjusted vertically and angularly with relation to the previously poured slab, such as 8, so as to position the concrete form 16 where desired for the pouring of the subsequent slabs. The concrete is poured over the lower form 16 and fills the space between the beams up to the dashed lines. The top of the concrete may be finished by trowel or otherwise. Thus, it is seen that only the lower and end frame members serve to mold the poured concrete, and that the top beam member serves as an extension for the support member 14. By the means described, a second circular slab or ring of roof structure is formed so as to join up and be integrally connected with the previously formed slab or ring such as 8 and will be supported thereby. When such a subsequent ring or slab has been formed either completely or part way around the previous slab, the cantilever frames and supported forms 16 should be moved forwardly so as to be supported by the slab just laid, but, of course, not until the concrete has set suificiently to sustain the weight of the cantilever frames, forms and the concrete etc.

By the means described, the cantilever frames are supported at offset locations on the top-forward and bottomrearward portions of the previously poured slab. In other words, the supports 14, 15 are spaced from each other more equally to distribute the forces in the supporting slab. In effect, therefore, the truss 13 is an extension of the lower beam 10 on the last poured ring or slab of concrete, the entire dome will be cantilevered out from the circular wall 5 and slabs or rings toward the center where the construction is complete.

It will be seen then that I have provided means for the building of a reinforced concrete dome-shaped roof Without the necessity for building up an expensive supporting superstructure for the concrete forms and that the support necessary for the concrete forms is cantilevered frame-work supported directly from the last previously laid ring or slab of concrete forming part of the dome.

In order to provide proper facility for workmen to do any patching necessary on the inside of the dome, the various frames may be provided with a walk-way 17 extending between frames in position so as to permit workmen to stand on the walks and perform any necessary operations on the inner side of the concrete dome.

It will be noted that where the concrete forms 16 approach each other, an opening may be formed which may be covered by sheet steel or plywood or the like.

. While the invention has been described in considerable detail and a preferred form illustrated, it is .to beflunderstood that changes may be made within the scope of the invention as defined in the appended claim.

I claim:

A removable frame structure for forming in slab sections a concrete dome-shaped roof, comprising a longitudinaily extending top beam means, a longitudinally extending lower beam means spaced from said top beam means and rigid therewith, said two beam means being spaced to receive a concrete form to be carried in the space between said two beam means, the length of the form corresponding substantially tothe radial length of a slab, first adjustable support means carried by said top beam means at a location to engage the top forward portion of a previously poured slab, said lower beam means comprising an extension member extending approximately a slab length, and second adjustable support means carried by said extension member at a location to engage the bottom rearward portion of the previously poured slab,

w P p, e-

whereby the adjustable support means engage the top and bottom of the poured slab and are adjustable to vary the longitudinal position of the beams on the previously poured slab and the angle of said beam means relative to said slab.

References Cited in the file of this patent UNITED STATES PATENTS 1,610,570 Milburn Dec. 14, 19-26 2,162,220 lessen June 13, 1939 2,308,806 Davis Jan. 19, 1943 2,493,264 Records Jan. 3, 1950 2,609,585 Ledbetter Sept. 9, 1952 2,649,643 Schutte Aug. 25, 1953 2,669,000 Seeman Feb. 16, 1954 2,857,647 Williams Oct. 28, 1958 I FOREIGN PATENTS 535,792 Germany Oct. 15, 1931 

